Endoscope apparatus of an endoscope cover system for preventing buckling of an endoscope cover

ABSTRACT

A cover system endoscope apparatus in which an insert part cover sheath for isolating the insert part of a cover endoscope is airtightly connected to a distal end constructive part of a tip part of an insert part cover. The insert part cover sheath is composed of a soft resin such as polyurethane exhibiting an excellent chemical resistance and a relatively high flexibility. The tip side of the cover sheath is connectively covered on an outer peripheral edge of the rear end of the distal end constructive part. The insert part cover sheath is formed with a forceps inlet on its near-at-hand side. Connected airtightly thereto is an endoscope manipulation part fixing mouth part having an expansion tube mouth for connecting an expansion tube and further a connecting part connected to a cover holding tool. An opening of an endoscope insert channel provided in an interior of the insert part cover sheath is formed on the near-at-hand side of the endoscope manipulation part fixing mouth part. The tip of the endoscope manipulation part fixing mouth part is connected to the distal end constructive part of the cover. Protruded are conduits such as air and water supply conduits and a channel communicating with a forceps outlet. These conduits are each formed of a soft resin such as PTFE exhibiting a low flexibility but a relatively high rigidity. A flexural rigidity when combining these conduits is larger than a flexural rigidity of the insert part cover sheath.

This application is a continuation-in-part of application Ser. No.08/391,464, filed Feb. 21, 1995, now U.S. Pat. No. 5,514,074, which is acontinuation of application Ser. No. 08/034,409, filed Mar. 19, 1993,now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscope apparatus of an endoscopecover system for installing an endoscope into an endoscope coverexpanded by an endoscope cover expander.

2. Description of the Related Art

In recent years, the endoscope apparatus has been widely employed in themedical field. The endoscope apparatus utilized in the medical sector isin some cases incapable of providing adequate viewing due to a bodyfluid adhered to a viewing window formed in the tip of an insert partwhen inserted into a living body. For this reason, an air or watersupply conduit is provided for removing the body fluid adhered to theviewing window by flushing a fluid over the viewing window. Some of theendoscope apparatuses are equipped with a suction conduit for suckingand discharging the useless body fluid.

Further, some are provided with a forceps channel (treatment toolchannel) whereby the tissues can be extracted by means of a living-bodyexamining forceps, or a medical treatment can be conducted by atreatment tool.

In the endoscope apparatus provided with the conduits such as the airsupply or the like and the forceps channel, cleaning and antibacterialtreatment are effected for surely preventing infectious diseases, etc.The complete antibacterial treatment and cleaning, however, aretime-consuming. There arise problems in which a using efficiency of theendoscope decreases, and workings such as the antibacterial treatmentare troublesome.

Under such circumstance, there is proposed a cover system endoscopeapparatus requiring no cleaning and no antibacterial treatment bycovering the endoscope itself in use with an endoscope cover to keep theendoscope itself clean.

For instance, Japanese Patent Laid-Open No. 3-29634 discloses a coversystem for covering the insert part of the endoscope by inserting itinto a cover (sheath). For facilitating an installation and removal ofthe endoscope insert part into and from the cover, the air is suppliedfrom a cover expander into the insert part cover into which theendoscope insert part is inserted.

The insert part cover is disposable so as not to form a hole in thecover sheath due to buckling when handled in the form of a single unitor not to be ruptured when used, and is composed of a resinous tube ofpolyurethane for providing strength. Further, in some types of endoscopeapparatuses, the insert part cover includes a channel for inserting theforceps and conduits for supplying air and water.

Those soft resinous tubes are formed of soft materials as are possibleto prevent an imbalance of flexibility in the cover endoscope insertedinto the cover. The tube is, however, required to have sufficientrigidity so as to not break a cavity of the tube itself or not causebuckling. The cover as a whole has a certain degree of flexuralrigidity.

That is, the insert part cover is, when the endoscope is not insertedtherein, easy to break and fold. Once the cover has a tendency of beingfolded, this portion is repeatedly folded with the result that pin holesare formed in the cover sheath. The cover is then unusable. Forenhancing the durability, the cover sheath is made resistant againstfolding by increasing both a thickness of the cover sheath and ahardness thereof.

The requirement of the disposable endoscope cover, however, may be adurability for one disease case. A larger thickness of the cover sheaththan needed leads to a futility of costs for materials. This causes anincrease in the price of product.

Further, the enhancement of the hardness provides a high resistanceagainst collapse but implies an easy-to-buckle state. The enhancementthereof is also apt to change the well-balanced flexibility of theendoscope according to the object and therefore worsen the insertabilitythereof.

By the way, the maximum bending angle of the endoscope is generallyadjusted in the course of manufacturing a single unit of an endoscope.One exemplification may be a known endoscope of such a system that aplurality of bending members are connected with rivets, and a bendingwire fixed to the tip part is pulled in by a near-at-hand manipulationpart, thus controlling the flexure. In this case, a stopper isincorporated in a pull-in device to which the wire is connectedinternally of the manipulation part. The stopper is fixed in amaximum-bending-angle position while measuring a bending angle of thetip part A maximum bending angle of the endoscope is set in this manner.Hence, when the angle is set once, the user is unable to simply alterthe angle.

The endoscope with the maximum bending angle set in this way isinstalled into the insert part cover. When controlling the flexure, abendable part of the endoscope undergoes a resistance of flexuralrigidity of the cover described above. The bendable part cannot betherefore bent up to the maximum bending angle set in the single unit ofendoscope. The maximum bending angle of the endoscope is set to anoperable angle with respect to a target organ, depending on a type ofthe endoscope. Therefore, if the maximum bending angle required is notobtained in a state of combination of the endoscope and the insert partcover as described above, this causes a problem wherein the operabilityof the endoscope declines.

SUMMARY OF THE PRESENT INVENTION

It is a primary object of the present invention to provide a coversystem endoscope apparatus capable of preventing buckling of anendoscope cover with a channel, being offered at a low price andexhibiting excellent operability while being easy to handle.

It is another object of the present invention to provide a cover systemendoscope apparatus capable of exhibiting excellent operability andobtaining a maximum bending angle needed in a state of combination of anendoscope and an endoscope cover by adjusting the maximum bending angleof the tip part of the endoscope so that the maximum bending angle ofthe tip part of a cover endoscope of the cover system endoscopeapparatus becomes a predetermined bending angle.

Briefly, according to one aspect of this invention, there is provided acover system endoscope apparatus comprising an endoscope and anendoscope cover for covering the endoscope. The endoscope cover includesa distal end constructive part, a proximal end constructive part and asoft tubular part through which the distal end constructive part and theproximal end constructive part ar airtightly connected. The tubular parthas a soft channel tube provided in the interior thereof. A rigidity ofthe channel tube is set larger than a rigidity of the tubular member.

Other objects and advantages of the present invention will becomeapparent during the following discussion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 through 10 are related to the first embodiment.

FIG. 1 is a view illustrating a whole configuration of a cover systemendoscope apparatus including a cover endoscope;

FIG. 2 is a view showing a constructive appearance of the coverendoscope;

FIG. 3 is a view illustrating a profile of a tip part of the coverendoscope;

FIG. 4 is a view illustrating a profile of a tip part of an insert partcover;

FIG. 5 is a sectional view showing a configuration of the principalportion of the cover endoscope;

FIG. 6 is an explanatory view showing maximum bending angles of a coverendoscope and of a single unit of endoscope;

FIGS. 7(a) and 7(b) are explanatory views showing how a universal cordcover is covered on a universal cord;

FIG. 8 is an explanatory view showing an overcoat tube covering thecover sheath during storage of the covering section;

FIG. 9 is a sectional view illustrating a configuration of a flexurecontrol device and a flexure control knob;

FIG. 10 is an explanatory view showing a configuration of a modifiedexample of the universal cord cover;

FIG. 11 is a sectional view illustrating a configuration of theprincipal portion of the cover endoscope in a second embodiment;

FIGS. 12 through 14 are related to a third embodiment;

FIG. 12 is a view illustrating an appearance of the tip part of theinsert part cover;

FIG. 13 is a view showing a profile of the tip part of the insert partcover;

FIG. 14 is a sectional view showing a configuration of the principalportion of the cover endoscope;

FIGS. 15 through 16(b) are related to a fourth embodiment;

FIG. 15 is a view illustrating a profile of the tip part of the insertpart cover; and

FIGS. 16(a) and 16(b) are sectional views showing a configuration of theprincipal portion of the cover endoscope.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first embodiment will hereafter be discussed. As illustrated in FIG.1, an endoscope equipment of an endoscope cover system (hereafter simplyreferred to as a cover system endoscope equipment) 1 is constructed ofan endoscope cove system endoscope apparatus (hereafter simply called acover system endoscope apparatus) 2 with a channel, a light source unit3, a video processor 4, a fluid control unit 5, an endoscope coverexpander (hereafter simply referred to as a cover expander) 6 with achannel ad a monitor 7. The endoscope apparatus 2 consists of achanneled endoscope cover (hereafter simply referred to as a cover) 2Aand a cover endoscope 2B covered with this cover. The light source unit3 supplies illumination light to this cover endoscope 2B. The videoprocessor 4 processes signals with respect to an imaging means built inthe cover endoscope 2B. The fluid control unit 5 supplies the air andwater via a tube of the cover 2A. The cover expander 6 is employed forcovering the cover endoscope with the cover 2A. The monitor 7 displaysan image signal processed by the video processor 4. A cart 8 encases thelight source unit 3, the video processor 4, the fluid control unit 5 andthe cover expander 6. The monitor 7 is mounted on the upper surface ofthe cart 8.

The following is a characteristic when effecting an examination by theendoscope. The clean cover endoscope 2B is covered with the clear cover2A. After the examination, the cover 2A is disposed of. Subsequently,the cover endoscope 2B is covered with a new clear cover 2A and thusrepeatedly used.

As shown in FIG. 2, the cover endoscope 2B comprises an endoscope insertpart (hereafter simply called an insert part) 11B, and an endoscopemanipulation part (hereafter simply referred to as a manipulation part)12B and a universal cord 13B. The insert part 11B is elongate andexhibits flexibility. The manipulation part 12B is formed at theproximal end of this insert part 11B. The universal cord 13B extendsfrom the side portion of this manipulation part 12B. A connector 14provided at the terminal of this universal cord 13B is detachablyconnectable to the light source unit 3. Because the connector 14 isconnected to this light source unit 3, a lamp provided in the interiorof the light source unit 3 supplies the illumination light to theterminal of an unillustrated light guide inserted through the universalcord 13B. Further, a cable 16 extends from the connector 14. A signalconnector 17 provided at the terminal of this cable 16 is detachablyconnectable to the video processor (see FIG. 1). Moreover, anantibacterial agent is coated on the outer surface of the insert part11B. Note that an application of the antibacterial agent of the insetpart 11B is not limited to the coating on the outer surface thereof butmay be infused into a material of the outer surface.

The manipulation part 12B includes a flexure control knob 15 provided onthe side opposite the side surface from which the proximal end of theuniversal cord 13B protrudes A bendable portion of a tip part 18a formedat the tip of the insert part 11B is bendable by manipulating thisflexure control knob 15. The manipulation part 12B is also provided withan air/water supply switch 12a, a suction switch 12b and an imagechangeover switch 12c, etc. The air/water supply, suction and imagefreezing can be performed by operating the respective switches.

The tip part 18a of the cover endoscope 2B is, as illustrated in FIG. 3,formed of a distal end constructive part 20 assuming a semi-circularshape in section. The end surface of the distal end constructive part 20is provided with an illumination optical system 20a and a viewingoptical system 20b.

On the other hand, the cover 2A is, as shown in FIG, 1, constructed ofan insert part covering section 11A, a manipulation part coveringsection 12a and a universal cord covering section (hereafter called acord cover) 13A which serve to cover respectively the insert part 1B,the manipulation part 12B and the universal cord 13B of the coverendoscope 2B.

A tip part 18b of the insert part covering section 11A is, asillustrated in FIG. 4, formed of a distal end constructive part 19. Thetip part 18b includes a transparent cover viewing window 21corresponding to the semi-circular shape of the tip part 18a of thecover endoscope 2B shown in FIG. 3. The tip part 18b further includesair/water supply nozzles 26 opened to the cover viewing window 21 and aforceps outlet 27. Connected airtightly to this distal end constructivepart 19 is an insert part cover sheath 38 for isolating the insert part11B of the cover endoscope 2B from the external environment.

The illumination light emitted from the light source unit 3 is led toone end surface of the light guide (not illustrated). The illuminationlight, as illustrated in FIG. 3, outgoes from the end surface of theillumination optical system 20a of the distal end constructive part 20of the inset part 11B toward a front subject via the cover viewingwindow 21 formed at the tip part of the insert part covering section11A. The light returned from the subject such as a diseased part isincident on the viewing window of the viewing optical system 20bprovided adjacent the illumination optical system 20a through the coverviewing window 21.

The viewing optical system 20b consists, as depicted in FIG. 5, of anobjective optical system 23 so attached to the viewing window 22provided inwardly of the cover viewing window 21 so as to confront thiswindow 21. An optical image is formed on a focal plane on this objectiveoptical system 23.

A CCD 24 is disposed on this focal plane. The optical image formedthereon is photoelectrically converted. The converted signal istransmitted to the video processor 4 via signal cables 25, 16 insertedthrough the insert part 11B and the universal cord 13B. After undergoingsignal processing, a standard video signal is generated. This videosignal is inputted to the monitor 7, whereby an image of the subject isdisplayed on a display screen.

The insert part cover sheath 28 is composed of a soft resin such aspolyurethane exhibiting an excellent chemical resistance and arelatively high flexibility (e.g., minor diameter: 10 mm, and thickness:0.2 mm). The top part thereof is connectively covered on the outerperipheral edge of the rear end of the distal end constructive part 19.A forceps insert port 29 is formed in a predetermined location of anear-at-hand portion is an endoscope manipulation part fixing mouth part35 including an expansion mouth 33 for connecting an expansion tube 32(see FIG. 1) and further a connection part 34 to be connected to a coverholding tool 10.

A near-at-hand portion 35a of this endoscope manipulation part fixingmouth part 35 is formed with an opening 37 of an endoscope insertchannel 36 provided inwardly of the insert part cover sheath 28.Further, the distal end of the endoscope manipulation part fixing mouthpart 35 is connected to the distal end constructive part 19 of thecover. Protruded are conduits such as an air supply conduit 38 (e.g.,minor diameter: 1.2 mm, and thickness: 0.3 mm), a water supply conduit(though not illustrated, e.g., minor diameter: 1.2 mm, and thickness:90.3 mm) each communicating with the air/water supply nozzle 26 and achannel 39 (e.g., minor diameter: 3.2 mm, and thickness 0.5 mm)communicating with the forceps outlet 27. The ends of the near-at-handportions of the air supply conduit 38 and the water supply conduit areherein connected to air/water supply sources (not illustrated). Theseconduits are each composed of a soft resin such as PTFE or the likeexhibiting a low flexibility and a relatively high flexural rigidity.The flexural rigidity when combined these conduits is larger than aflexural rigidity of the insert part sheath 28.

The tip of the insert part 11B of the cover endoscope 2B is providedwith a bendable part 40a. The bendable part 40a is formed by connectinga plurality of non-circular tubular bendable members 40 with rivets 41in continuation from the distal end constructive part 20. A wireinsertion restrictor 43 protruding inward is provided in the bendablepart 40 corresponding in the bending direction. A flexural control wire44 connected to the distal end construction part 20 of the coverendoscope 2B is inserted into an interior of this wire insertionrestrictor 43. A rear end of the flexural control wire 44 is connectedto a bending device incorporated into the manipulation part 12B., whichwill be mentioned later. This bending device includes, though not shown,a known stopper for regulating a bending angle, thereby determining themaximum bending angle of the tip part 18 of the cover endoscope 2B.

FIG. 6.(a) shows an external appearance of the tip part of the coverendoscope with the insert part covering section 11A when bent at themaximum. FIG. 6(b) shows that of a single unit of endoscope 2B when bentat the maximum. The maximum bending angle β of the single coverendoscope 2B is set larger than the maximum bending angle α required forthe endoscope when covered with the insertion part covering section 11A.A value obtained by β-α/α at this time is, though different depending ona magnitude of the flexural rigidity of the insert part covering section11A to be assembled, desirably about 5˜20%. For instance, β is set at170° in this case. When assembled in the insert part covering section11A, the maximum bending angle becomes 160°.

FIG. 7 is an enlarged view of the connecting part of the cord cover 13A.FIG. 7(a) shows a state before being connected. FIG. 7(b) shows a stateafter being connected.

As illustrated in FIG. 7(a), the universal cord 13B on the side of themanipulation part 12B is connected via a connecting proximal part 45 tothe manipulation part 12B. A small-diameter fixing groove 46 is cut insome of the outer peripheral surface of the connecting proximal part 45so as to extend along the entire periphery thereof.

On the other hand, the cord cover 13A consists of a cover 47 composed ofa cylindrical soft plastic material and fixing members 48 provided onthe inner peripheral surface of the end part thereof. The fixing membersare a plurality of Segments, each assuming a fan-shape in section, of anannular magnetic part having a minor diameter smaller than a majordiameter of the fixing groove 46 on the side of the universal cord 13B.The fixing members 48 are allocated substantially uniformly along theinner peripheral surface of the cover 47. An outer periphery each of thefixing members 48 is bonded to the inner surface of the cover 47. Then,as illustrated in FIG. 7(b), the fixing members 48 are fitted in thefixing groove 46, thus making a magnetic connection.

As illustrated in FIG. 8, when storing the insert part covering section11A, the cover sheath 28 is covered with an overcoat tube 49. The coversheath 28 is connectively secured to the endoscope manipulation partfixing mouth part 35 through an opening unit 50 provided on thenear-at-hand side of the overcoat tube 49. A lubricating material 51(e.g., xylocain jelly) employed for improving the insertability of theendoscope is sealed between the cover sheath 28 and the overcoat tube49.

FIG. 9 is a sectional view showing the flexural control device 52incorporated into the body of the manipulation part device 12B and theflexural control knob 15. A pair of upper and lower pulleys 54, 55 aredisposed in a casting 53 of the manipulation part 12B. The lower pulley55 is formed integrally on the proximal end portion of the firstcylindrical rotary shaft 56. One manipulation wire 44a described aboveis wound on the pulley 55. The first rotary shaft 55 is axiallyrotatable supported on a support shaft 58 projecting from a proper baseplate 57 provided inwardly of the casting 53. The tip of the firstrotary shaft 56 is protruded externally of the casting 53. A firstflexural control knob 15a is fitted in a location apart from the casting53.

Further, the upper pulley 54 is formed integrally on the proximal partof a second rotary shaft 59 rotatably attached to the first rotary shaft56. The other manipulation wire 444b is wound on the pulley 54. The tipof the second rotary shaft 59 extends to substantially the same lengthas the lower surface of the first flexural control knob 15a. A secondcontrol knob 15b is fitted to the tip of the second rotary shaft 59.

A first friction ring 60 is provided between the base plate 57 and thepulley 55. A second friction ring 61 is provided between themanipulation part casing 53 and the pulley 54. Seal parts 62, 63, 64serve to ensure a watertightness between the respective parts.

The following is an explanation of a method of assembling those partsdescribed above.

Firstly, after bonding the transparent viewing window 21 to the distalend construction part 19, the air supply conduit 38, the water supplyconduit (not shown) and the channel 39 (PTFE, minor diameter: 3.2 mm,and thickness: 0.5 mm) are connected to the rear end thereof. A sidehole 42 is formed in the rear end portion of the channel 39 adaptivelyin a position corresponding to the forceps inlet 29 when the endoscopemanipulation mouth part 35 is connected. The side hole 42 is longer thenthe minor diameter of a forceps inlet 29 but shorter than a fittinglength of the endoscope manipulation part fixing mouth part 35 and thechannel 39.

Secondly, the insert part cover sheath 28 is correctively covered on theouter periphery of the rear end portion of the distal end constructivepart 19. The cover sheath 28 is previously worked to a predeterminedlength corresponding to the length of the insert part of the coverendoscope.

Thirdly, the air supply conduit 38, the water supply conduit (notillustrated) and the channel 39 are inserted into the endoscopemanipulation part fixing mouth part 35 The rear end portion of theinsert part cover sheath 28 is connected to the front end portion of theendoscope manipulation fixing mouth part 35. At the same time, therespective conduits and the insert part cover sheath 28 are airtightlyfixed to the endoscope manipulation part fixing mouth part 35.

It is therefore possible to reduce a scatter in the length of the insertpart covering section 11A because of such an assembling step that adistance between the distal end constructive part 19 and the endoscopemanipulation part fixing mouth part 35 is determined only by the lengthof a single part of the insert part cover sheath 28.

The operation of the cover system endoscope apparatus as so constructedwill be described.

As in the typical endoscope cover fitting method, the inset partcovering section 11A is taken out of an unillustrated cover storagepackage containing the antibacterial endoscope cover 2A. The insert partcovering section 11A is covered with the overcoat tube 49 and can betherefore held by the cover holding tool 10 while keeping anantibacterial state of the cover sheath 28 even when an assistant in anunclean area holds and takes it out At this moment, the lubricatingmaterial 51 sealed in the overcoat tube 49 acts to reduce the frictionresistance cause when removing the insert part covering section 11A fromthe overcoat tube 49. Further, the lubricating material 51 is adhered tothe surface of the cover sheath 28 of the insert part covering section11A.

The cover expander 6 is employed when mounting the insert part coveringsection 11A on the insert part 11B of the cover endoscope 2B and whenremoving the insert part 11B from the insert part covering section 11A.

This cover expander 6 is constructed basically of an air supply pump(not illustrated) and an air supply conduit (not illustrated). Anopening end of the air supply conduit is provided with a mouth ring forconnecting the proximal portion of the expansion tube 32. This coverexpander 6 normally continues to supply the air. For this reason, if thefunction of the cover expander 6 is not used, as illustrated in FIG. 1,the terminal of the expansion tuber 32 is not connected to an expansiontube mouth 33 but opens to the outside air for air leakage.

Then, when inserting and removing the cover endoscope 2B into and fromthe insert part covering section 11A, the terminal of the expansion tube32 is intruded into the expansion tube mouth 33 and thus airtightlyconnected thereto by insertion (fitting). The air is fed via theexpansion tube mouth 33 into the endoscope insertion channel 36, therebyexpanding the endoscope insertion channel 36. It is thus possible toeasily insert and remove the endoscope insert part 11B.

When inserting the cover endoscope 2B into this insert part coveringsection 11A, a flange part of the upper end of the endoscopemanipulation part fixing mouth part 35 is held by a semi-circularholding part 10a formed in the cover holding tool 10. In this state, theinsert part 11B of the cover endoscope 2B is inserted from the endoscopemanipulation part fixing mouth part 35, thus facilitating theinstallation.

Next, the cord cover 13A is covered from the other end of the connectingproximal part 45 of the universal cord 13B. At this time, the fixingmembers have already been segmented, and the end portion of the cover 47is therefore opened wide. Just when the end portion comes to the fixinggroove 46, the respective fixing members 48 are so connected by themagnetic force as to be covered on the fixing groove 46, thus fixing theend portion. After the endoscope cover 2A has been mounted, the insertpart covering section 11A incorporating the insert part 11B is insertedinto the body of the patient.

The maximum bending angle of the tip of the cover system endoscopeapparatus 2 is smaller than the maximum bending angle β(170°) of thecover endoscope 7 depending on the flexural rigidity of the insert partcovering section 11A itself. As a result, the former bending angle comesto the maximum bending angle α(160°) required for the cover systemendoscope apparatus 2.

Further, friction resistance is applied on the flexure control knob 15during the flexure control. The bending angle can be fixed in anarbitrary position. Simultaneously, if the endoscope is mistakenlyremoved while the tip bendable portion remains bent, the pulley slideson the friction ring, and the flexure is returned to a straightposition.

As described above, according to the cover system endoscope equipment 1in this embodiment, the flexural rigidity when combining the air supplyconduit, the water supply conduit and the channel is set larger than theflexural rigidity of the insert part cover sheath. Hence, it is possibleto provide a structure in which the insert part covering section is hardto buckle at a low price without losing the flexibility balance of theinsert part of the cover endoscope. It is also feasible to improve theoperability and ease of handling. Further, the durability of the coversheath can be restrained down to a level required enough to bedisposable. The manufacturing costs can be therefore reduced.

Moreover, the outer peripheral edge of the rear end of the distal endconstructive part 19 is covered with the tip part of the cover sheath.The edge is not exposed to the outside and does not therefore causedamage within the body cavity.

Besides, the maximum bending angle of the tip part 18 of the singlecover endoscope 2B is set larger than the maximum bending angle neededwhen assembling the cover 2A. Hence, even if the bending angle isdecreased due to the flexural rigidity of the insert part coveringsection 11A, it is possible to obtain the maximum bending angle requiredfor the cover system endoscope apparatus 2.

Furthermore, friction resistance is applied on the flexure control knob15 during the flexure control, and the bending angle can be fixed andheld in an arbitrary position. At the same time, if the endoscope ispulled out while the bendable portion of the tip part remains bent, thepulley slides on the friction ring. The flexure is returned straight.Hence, the cover endoscope 2B can be removed safely without damaging thewall of the body cavity.

Further, antibacterial coating is applied on the insert part 11B of thecover endoscope 2B. It is therefore feasible to prevent a propagation ofvarious germs during the storage.

Besides, the fixing members 48 are connected by the magnetic force inthe fixing groove 46 formed in the connecting proximal part 45 of theuniversal cord 13B, thus fixing the end portion. The universal cordcover 13A is therefore simply attached and detached Because of beingsecured in the fixed groove 46, there is no possibility of contaminatingthe cover endoscope 2B due to a shift when used.

Further, the insert part covering section 11A is covered with theovercoat tube 49, thereby preventing contamination on the insert partcovering section 11A. At the same time, the lubricating material 51 issealed in the overcoat tube 49. It is thus feasible to readily pull theinsert part covering section 11A out of the overcoat tube 49.Furthermore, even after removing the insert part covering section 11Afrom the overcoat tube 49, the lubricating material is coated on thesurface of the cover sheath 28, there is no necessity for applying thelubricating agent each time a part of the cover system endoscopeapparatus 2 is inserted in to the body cavity. The examination can bequickly conducted.

Note that the universal cord cover 13A is constructed so that the fixingmembers 48 are connected by the magnetic force in the fixing groove 46formed in the connecting proximal part 45 of the universal cord 13B.However, the construction is not limited to that above-mentioned. Auniversal cord cover shown in FIG. 10 may be available.

As illustrated in FIG. 10, a universal cord cover 70 provided by was ofa modified example is constructed of a cover 71 and fixing members 72.The cover 71 is composed of a cylindrical soft plastic material. Thefixing members 72 are provided on the inner peripheral surface of theend portion thereof. The fixing members 72 are a plurality of segments,each assuming a fan shape in section, of an annular hard plasticmaterial to have a minor diameter smaller than a major diameter of thefixing groove on the side of the universal cord. A projection 74 and anengagement groove 73 which engage with each other are formed on and inconnecting surfaces of adjacent fixing members 72. The fixing members 72are allocated substantially uniformly along the inner peripheral surfaceof the end portion of the cover 71. An outer periphery of each of thefixing members 72 is bonded to the inner surface of the cover 71.

The universal cord cover 70 is covered from the other end of theconnecting proximal part 45 (see FIG. 5(a)) of the universal cord 13B.At this moment, the fixing members 72 have been already segmented, andthe end portion of the cover 71 is therefore opened wide. Just when theend portion of the cover 71 comes to the fixing groove 46, theprojection 74 and the engagement groove 73 of the respective fixingmembers 72 are so connected as to be covered on the fixing groove 46,thus fixing the end portion.

In the universal cord cover 70 thus shown by way of the modifiedexample, the fixing members 72 are manufactured in the form of plasticmolded parts. Hence, reductions both in price and in weight can beattained.

Next, a second embodiment will be discussed. The second embodiment issubstantially the same as the first embodiment except that a differentarrangement is to be explained. The same components are marked with thelike symbols, and the explanation is therefore omitted.

As illustrated in FIG. 11, the tip part 18b of the insert part coveringsection in the second embodiment is constructed as follows. A first airsupply conduit 38a, a water supply conduit (not shown) and a channel 39aare connected to the distal end constructive part 19. The rear endsthereof are connected to an endoscope manipulation part fixing mouthpart 35a. A helical groove 80 is cut in the outer peripheral surface ofthe channel 39a. Further, a second air supply conduit 38b, a watersupply conduit (not illustrated) and a channel 39b are protruded fromthe rear end of the endoscope manipulation part fixing mouth part 35a. Adistance L2 of the cover sheath 28 is set slightly larger than adistance L1 of each of the air supply conduit 38a, water supply conduit(not shown) and channel 39a between a rear end surface 81 f the distalend constructive part 19 and a front end surface 82 of the endoscopemanipulation part fixing mouth part 35a. Other configurations andoperations are the same as those in the first embodiment.

According to the cover system endoscope apparatus thus constructed inthe second embodiment, the helical groove is formed in the channelwithin the insert part covering section. Hence, there is no possibilityof reducing the flexibility of the covering section as a whole even whenenhancing the rigidity of the channel for improving the resistanceagainst buckling of the covering section. There is also no possibilityof deteriorating the insertability because of consequently losing theflexibility balance of the cover endoscope when installed.

Further, the distance L2 of the cover sheath is set longer than thedistance L1 of the conduit such as the channel, etc. The ease ofinstalling the cover endoscope does not worsen due to slackening of theconduit like the channel in the covering section.

Next, a third embodiment will be discussed. The third embodiment issubstantially the same as the first embodiment, only the differentconfiguration will be explained. The same components are marked with thelike symbols, and the description is therefore omitted.

As illustration in FIG. 12, solely-water-soluble high polymers 91 arecombined by graft polymerization on the outer surface of an insert part11B.

The tip part 18b of the insert part covering section 11A is, anillustration in FIG. 13, formed of the distal and constructive part 19.The tip part 18b includes a transparent cover viewing window 21corresponding to the semi-circular shape of the tip part 18b of thecover endoscope 2B as shown in FIG. 3. The tip part 18b further includesan air supply nozzle 26a, a water supply nozzle 26b opened to the coverviewing window 21 and a forceps outlet 27. Connected airtightly to thisdistal end constructive part 19 is an insert part cover sheath 28 forisolating the insert part 11B of the cover endoscope 2B from theexternal environment. This insert part cover sheath 28 is composed of atube in which the solely-water-soluble high polymers 92 are combined bythe graft polymerization on the outer surface of a soft resin such aspolyurethane exhibiting an excellent chemical resistance and arelatively high flexibility.

A near-at-hand portion 35a of the endoscope manipulation part fixingmouth part 35 is, as shown in FIG. 14, formed with an opening 37 of anendoscope insert channel 36 provided inwardly of the insert part coversheath 28. Further, the distal end of the endoscope manipulation partfixing mouth part 35 is connected to the distal end constructive part 19of the cover. Protruded are conduits such as an air supply conduit 38, awater supply conduit (though not illustrated) respectively communicatingwith the air supply nozzle 26a and the water supply nozzle 26b and alsoa channel 39 communicating with the forceps outlet 27. The ends of thenear-at-hand portions of the air supply conduit 38 and the water supplyconduit are herein connected to air/water supply sources (notillustrated). These conduits are each composed of a soft resin such asPTFE or the like exhibiting a low flexibility and a relatively highflexural rigidity.

The outer periphery of a bendable part 40 is covered with a tubularbendable rubber 101 that is soft and stretchable. Connected via aconnecting tube 103 to the rear end of the bendable part 40 is aflexible tubular part 107 consisting of a metallic band-like helicaltube 104, a cylindrical steel tube 105 and an insert part sheath 106formed of a soft resin. The rear end of the flexible tubular part 107 isconnected to a manipulation part 12.

Note that a flexibility is given to each of the conduits such as the airsupply conduit 38, the water supply conduit (not shown) and the channel39 and also the insert part covering section 11A incorporating theseconduits, and this flexibility is set larger than a flexibility of theflexible tubular part 107 of the cover endoscope 2B that is insertedinto the endoscope insert channel 36.

Herein, the insert part cover sheath 28 is formed of a soft resin whichis very thin, e.g., 0.2 mm and therefore exhibits a large flexibility.Besides, the air supply conduit 38, the water supply conduit (notillustrated) and the channel 39 are preferably made of Teflon. Theseconduits each have a small diameter and are therefore large in terms offlexibility. For instance, the air supply conduit 38 and the watersupply conduit (not shown) each have a minor diameter of 1.2 mm and athickness of 0.3 mm. The channel 39 has a minor diameter of 2.8 mm and athickness of 0.45 min. On this assumption, a relationship in themagnitude of flexibility between these conduits is given such as:

Channel 39<Air supply conduit 38=Water supply conduit<Insert part coversheath 28

On the other hand, for example, the band-like helical tube 104 of theflexible tubular part 107 is formed of stainless steel to have athickness of 1.0 min. The cylindrical steel tube 105 is formed of apolyimide resin, and a strand is 0.12 mm. Further, the insert pathsheath 106 is compose of polystyrene and is 0.6 mm in thickness. Theinsert part sheath 106 permeates and is solidified in a gap of thecylindrical steel tube 105. The total flexibility of the flexibletubular part 107 is smaller than that of the insert part coveringsection 11A. Other configurations are the same as those in the firstembodiment.

The following is an explanation of the operation of the thus constructedcover system endoscope apparatus.

As in the typical endoscope cover fitting method, the insert partcovering section 11A is taken out of the storage package of the cover(not illustrated) containing the antibacterial endoscope cover 2A.

When inserting the cover endoscope 2B into the insert part coveringsection 11A, a flange of the upper end of the endoscope manipulationpart fixing mouth part 35 is held in the semicircular holding part 10a(see FIG. 1) formed in the cover holding tool 10. In this state, theinsert part 11B of the cover endoscope 2B is inserted from the endoscopemanipulation part fixing mouth part 35. Thus, an easy installation canbe done. At this time, a small amount of water content is added to theinsert part 11B of the cover endoscope 2B. Graft chains of water-solublehigh polymers 91 combined on the outer surface of the insert part 11Btake in the water content and change into a well-lubricated slimy state.This facilitates the insertion thereof.

After installing the endoscope cover 2A, the insert part cover section11A including the insert part 11B is inserted into the patient's body.At this moment, the graft chains of water-soluble high polymers 92combined on the surface of the insert part cover sheath 28 taken in abody fluid enough to assume the well-lubricated slimy sate. Theinsertion into the body cavity is thus facilitated. Other operations arethe same as those in the fist embodiment.

As discussed above, according to the cover system endoscope apparatus inthis embodiment, the flexibility of the insert part covering section 11Ais set higher than the flexibility of the flexible tubular part 107 ofthe cover endoscope 2A that is inserted into the endoscope insertchannel 36. Namely, the conduits such as the air/water supply conduitsand the channel in the insert part covering section 11A are moreflexible than the insert part 11B of the cover endoscope 2A.Accordingly, the air/water supply conduits and the channel are notbroken previously owing to the flexural manipulation during theinsertion of a part of the cover system endoscope apparatus into thebody cavity.

Further, the respective conduits are made confluent in the vicinity ofthe distal end constructive part, and the air and water are supplied viaone nozzle provided at the tip. This conventional system is intricate interms of structure of the confluent portions and is high in price. Theconventional system is not suited to the insert part cover on thepremise of the disposable application. In accordance with embodiment,however, there are provided conduits dedicated to the supply of waterand air, respectively. These conduits are independently connected to thenozzle of the distal end constructive part. This arrangement makes easythe control through the electromagnetic valve as well as deceasing theprice.

Note that the water-soluble high polymers 91 are combined by the graftpolymerization on the outer surface of the insert art 11B to improve theinsertability of the insert part 11B. The present invention is not,however, limited to this arrangement. The water-soluble high polymersmay be graft-combined on the inner surface of the insert part coversheath 28. In addition, these two arrangements may be employed incombination. The combinational use further ameliorates the insertabilityof the endoscope insert part.

Next, a fourth embodiment will be discussed. The fourth embodiment issubstantially the same as the third embodiment. The same components aremarked with like symbols, and the description is therefrom omitted.

As illustrated in FIG. 15, the tip part 18b of the insert part coveringsection in the fourth embodiment consists of the distal end constructivepart 19. The tip part 18b includes the transparent viewing window 21corresponding to the semi-circular shape of a distal end constructivepart 20 of the cover endoscope 2B as shown in FIG. 3. The tip part 18bfurther includes an air/water supply nozzle 110 opened to the viewingwindow 21 and a forceps outlet 27. The air/water supply nozzle 110 isembedded in the tip surface of the distal end constructive part 19. Onlya nozzle end portion 112 is protruded from the tip surface, and anopening 113 is directed to the viewing window 21.

As shown in FIG. 16(a), the air/water supply nozzle 110 consists of abase part 111 taking an elliptical shape in section and the nozzle endportion 112. The air/water supply nozzle 110 has a branch conduit 114branching off in two ways in the base part 111 so as to communicate theopening 113 of the nozzle end portion 112. The rear end of the branchconduit 114 communicates with an air supply conduit 115 and a watersupply conduit 116 connected to the distal end constructive part 19 viaa connecting conduit 114a provided in the distal end constructive part19.

As shown in FIG. 16(b), a diameter of the water supply conduit 116 witha high-viscosity fluid flowing therethrough is larger than a diameter ofthe air supply conduit 115. The water supply conduit 116 having thelarger diameter is disposed closer to the cross-sectional center of theinsert part covering section 11A than the air supply conduit 115.Near-at-had portions of the air and water supply conduits 115, 116 areconnected to air and water supply sources (not illustrated). Further,the air and water supply conduits 115, 116 are provided on the same sideas the channel 39 to extend along the channel 39 communicating with theforceps outlet 27 and accommodated in the tip part cover. Incidentally,the numeral 120 designates a light guide for transmitting theillumination light to an illumination optical system 20a.

The forceps channel 39 is arranged on a side off-center from an insertpart bending axis 122. The water supply conduit 116 and the air supplyconduit 115 are arranged on the other side of the bending axis 122.

That is, as is generally arranged, the location of a forceps channelalong a center line of the bending axis on upper, lower, right and leftsides creates a problem in the bending action of the endoscope. Forexample, where a desired bending angle cannot be obtained because theforceps channel, which is the largest diameter conduit, tends to providea resistance to the bending motion, requiring increased power as thebending motion increases, so that the forced bending action tends todeform the forceps channel.

However, in this embodiment, as shown in the arrangement in FIG. 16(b),the resistance to bending caused by the forceps channel 39 is small inthe upper, lower, right and left bending directions which are often usedgenerally in comparison with that of the channel arranged at the centerline. Thus, only a small amount of power is required to bend channel 39to a desired angle. The channel is easily bent in even the unfavorabledirection and deformation can be prevented.

Other configurations and operations are the stone as those in the thirdembodiment.

According to the cover system endoscope apparatus of the fourthembodiment, the following advantages are given in addition to those inthe third embodiment. The air and water supply conduits are disposed inthe side-by-side relationship on the same side as the channel. It istherefore possible to miniaturize and simplify the confluent structureof the conduits at the tip part. Besides, the conduit having the largediameter is disposed closer to the cross-sectional center of the insertpart covering section. An in-cover filling rate increases enough toreduce the diameter of the cover section.

It is apparent that, according to this invention, a wide range ofdifferent working modes can be formed based on the invention withoutdeviating from the spirit and scope of the invention. This invention isnot restricted by its specific working modes except by the appendedclaims.

What is claimed is:
 1. A cover system endoscope apparatus comprising:anendoscope having a bendable insert part, said insert part being bendablealong a defined center axis of bending which exists in a vertical planein the longitudinal direction of said insert part; and an endoscopecover for covering said endoscope, said endoscope cover including:adistal end constructive part; a proximal end constructive part; and asoft tubular member through which said distal end constructive part andsaid proximal end constructive part are airtightly connected, saidtubular member having a soft channel tube provided in an interiorthereof, wherein said channel tube includes at least an air supplyconduit, a water supply conduit and a forceps insert conduit, saidforceps insert conduit having the largest diameter among said conduitsand being disposed in a position which is off-center from said centeraxis of bending, said air supply conduit and said water supply conduitare disposed in a side-by-side relationship on one side of said forcepsinsert conduit, and said air supply conduit and said water supplyconduit being joined at the distal end so as to communicate with anozzle formed in said distal end constructive part.
 2. A cover systemendoscope apparatus according to claim 1, wherein said insert part ofsaid endoscope has a bendable portion for defining said center axis ofbending.